A Study of Multi-Pass Laser-Cladding 2205 Duplex Stainless Steel Coating: Microstructure, Electrochemical Corrosion Behavior, and Wear-Resistance Properties

By applying 2205 duplex stainless steel powders to repair and improve carbon steel, multipass laser-cladding tests were conducted on Q235 carbon steel surfaces with different laser powers in the range of 1.9-2.5 kW in order to evaluate the performance of the laser-cladding layers. The phase composition, macro- and microstructure, electrochemical corrosion resistance, friction, and wear resistance of the laser-cladding layers were investigated. Macroscopic observation identified no obvious cracks. The phases that made up the multi-pass laser-cladding layers were gamma-Fe and alpha-Fe. Owing to the optimal laser power at 2.3 kW, a large number of equiaxed crystals and a small number of cellular crystals made up the microstructure of the prepared laser-cladding layer, which contributed to its good corrosion resistance. The wear resistance of the multi-pass laser-cladding layer and the carbon steel was also studied. A combined action of adhesive wear and abrasive wear, accompanied by oxidative wear, was determined through observation of pits and furrows on the friction surface of the multi-pass laser-cladding layer, while a typical mechanism of abrasive wear was confirmed by checking the friction surface of the carbon steel.